Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;

public class Main {
    public static String calculateMd5Checksum(String filename) {
        String result = "";
        try {
            byte[] b = createChecksumBytes(filename, "MD5");
            // convert bytes to HEX strings
            for (int i = 0; i < b.length; i++) {
                result += Integer.toString((b[i] & 0xff) + 0x100, 16).substring(1);
            }
        } catch (Exception ex) {
            throw new RuntimeException("Error: " + ex.toString(), ex);
        }
        return result;
    }

    public static byte[] createChecksumBytes(String filename, String checksumType)
            throws java.io.IOException, java.security.NoSuchAlgorithmException {
        if (checksumType == null) { // MD5 by default
            checksumType = "MD5";
        }
        java.io.InputStream fis = new java.io.FileInputStream(filename);

        byte[] buffer = new byte[1024];
        java.security.MessageDigest complete = java.security.MessageDigest.getInstance(checksumType);
        int numRead = 0;

        do {
            numRead = fis.read(buffer);
            if (numRead > 0) {
                complete.update(buffer, 0, numRead);
            }
        } while (numRead != -1);

        fis.close();
        return complete.digest();
    }
}